Browsing by Author "Lu, PH"

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A microstrip elliptic function filter with compact miniaturized hairpin resonators
(2000-03-01)
Kuo, JT
;
Maa, MJ
;
Lu, PH
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電信工程研究所
;
Institute of Communications Engineering
A four-pole elliptic function bandpass filter is designed using compact miniaturized microstrip hairpin resonators. It is shown that the filter occupies a very small area. The full-wave simulator IE3D is used to design the resonator and to calculate the coupling coefficients of the three basic coupling structures. Measurement results are compared with the computed responses.
Design techniques for VHF/UHF high-Q tunable bandpass filters using simple CMOS inverter-based transresistance amplifiers
(1996-05-01)
Lu, PH
;
Wu, CY
;
Tsai, MK
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, CMOS inverter-based wideband transresistance R(m) amplifiers are proposed and analyzed. Using the R(m) amplifiers, tunable VHF/UHF R(m)-C bandpass biquadratic filters can be designed. In these filters, the center frequency f(o) can be post-tuned by adjusting the control voltages of the R(m) amplifiers. The pseudodifferential configuration uses the extra inversely connected and self-shorted inverters for Q enhancement. Experimental results have shown that the center frequency f(o) of the single-ended-output R(m)-C bandpass biquad is 386 MHz (258 MHz) and Q = 1.195 (Q = 1.012) for +/-2.5 V (+/-1.5 V) supply voltage. The power consumption is 24.83 mW (3.42 mW), and the dynamic range is 61 dB (55.5 dB). For pseudodifferential-output high-Q configuration, the measured quality factor Q can be as high as 360 with f, = 222.7 MHz. When Q = 94, the power consumption is 56.2 mW and the measured dynamic range is 57.8 dB for +/-2.5 V supply voltage.
Joint design of interpolation filters and frequency equalizers in DMT systems for XDSL applications
(2005)
Cheng, MH
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Lu, PH
;
Wu, JF
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電控工程研究所
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Institute of Electrical and Control Engineering
We formulate the joint design of interpolation filter and frequency equalizer in DMT systems as the problem for minimization of the mean square error between the input data symbol and its output estimate. Then an iterative algorithm is proposed for solution. Each iteration requires only solving two quadratic minimizations; the algorithm also ensures convergence. Simulations for VDSL applications demonstrate that an increment in transmission rate can be achieved compared with the conventional design of the interpolation filter and frequency equalizer separately.